The two workplaces now join the Health Department and the Australia Bureau of Statistics, which have already announced they will retrench staff to deal with the government's economy drive.

Community and Public Sector Union national secretary Nadine Flood said the deep cuts announced in the mid-year budget review meant job losses were inevitable.

''This is bad news for DEEWR employees, but it's also a concern for the many businesses and organisations that rely on the important work these people do. For a government so focused on employment, cutting 500 jobs from your own employment department is not a great look.''

She said the bureaucracy would lose talented staff with skills ''built up over many years''.

''It will take a generation to recover. It is a false economy.''

The Education Department said it would offer voluntary redundancies, as staff attrition alone was unlikely to lead to 500 job losses in a year. Its secretary, Lisa Paul, said: ''While we anticipate that essentially all areas of the department will be impacted by the reduced budget, those impacts will … help inform how many VRs we offer and where … While we will continue to look for savings in areas such as travel and property, we will need to reduce staff.''

The government's budget review, issued in late November, revealed Labor would raise the ''efficiency dividend'' from 1.5 per cent to a record 4 per cent in 2012-13.

Finance Minister Penny Wong said much of the money could be saved without sacking staff, by reducing spending on consultants, advertising and travel.

The Treasury could not be contacted last night about its plans to reduce its workforce.